In vitro evaluation of the total phenolic and flavonoid contents and the antimicrobial and cytotoxicity activities of crude fruit extracts with different polarities from Ficus sycomorus

Abstract

Plants are a good source for discovering new drugs for human benefit. The objective of this study was to determine the total phenolic and flavonoid contents and to probe the antimicrobial and cytotoxic activities of fruit extracts of Ficus sycomorus (F. sycomorus), which is native to the Sultanate of Oman. A study was conducted to measure the total phenolic and flavonoid contents of the methanol extract of this fruit and its derived fractions [n-hexane, chloroform, ethyl acetate, butanol and residual aqueous fractions] by in vitro chemical analyses using the Folin-Ciocalteu reagent assay (FCR) and the aluminium chloride (AlCl₃) method. The antimicrobial and cytotoxic activities were assessed using the slightly modified agar disc diffusion method and the brine shrimp lethality (BSL) method. The results of the analysis of the total phenolic content in different fruits extracts showed a significant amount of phenolic compounds, ranging from 1.48 to 213.79 mg of GAE/100 g of powder weight. However, the range of the total flavonoid content among the fruit extracts was found to be 0.100–0.527 mg QE/100 g of powder weight. The antimicrobial activity of the crude fruit extracts at different concentrations against four Gram-positive and Gram-negative bacterial strains, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Haemophilus influenza (H. influenza), and Proteus spp (P. spp), showed strong activity in the range of 0–15 mm. The highest cytotoxic activity among the same extracts was that of the methanol extract, which had a LC₅₀ value of 1.48 μg/mL, followed by hexane, chloroform, butanol, water and ethyl acetate, with LC₅₀ values of 2.13, 3.16, 7.49, 133.04, and 213.79 μg/mL, respectively, in comparison to the control, DMSO. The findings of the present study suggest that the fruit extracts have significant amounts of total phenolic and flavonoid compounds with potential cytotoxic and antimicrobial activities.